Electronic device which can detect touch state

ABSTRACT

An electronic device which can detect a touch state, comprising: a front surface for showing images; at least one first electrode, provided in a first region; at least one second electrode, provided in a second region, wherein a distance between the first region and the front surface is larger than a distance between the second region and the front surface; a capacitance calculating circuit, configured to calculate at least one first capacitance generated by the first electrode and coupled to the second electrode to calculate at least one second capacitance generated by the second electrode, wherein the capacitance calculating circuit further calculates a capacitance difference between the first capacitance and the second capacitance; and a processing circuit, configured to determine the touch state according to the capacitance difference. Via such structure, the touch state of the electronic device can be precisely acquired.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a continuation of applicant's earlier application,Ser. No. 16/748,746, filed 2020 Jan. 21, and is included herein byreference.

BACKGROUND OF THE INVENTION 1. Field of the Invention

The present invention relates to an electronic device capable ofdetecting a wearing state or a touching state, and particularly relatesto an electronic device having at least one electrode to detect awearing state or a touching state.

2. Description of the Prior Art

In recent years, a smart wearable electronic device such as a smartwatch or a smart wristband has become more and more popular. Such smartwearable electronic device always has various functions, such as mobilepayment or biological information detection (e.g. heart rate). However,the biological information detection may fail or non-accurate if theuser does not wear the smart wearable electronic device in a propermanner. Also, the smart wearable electronic device always needs to berecognized before using the mobile payment. If the smart wearableelectronic device is stolen after being recognized, someone who stealsit can use this device to pay any bill. However, no security mechanismis provided to avoid such issue.

SUMMARY OF THE INVENTION

One objective of the present invention is to provide an electronicdevice with a function of detecting a touch state.

One embodiment of the present invention provides an electronic devicewith a function of detecting a touch state, comprising: a front surface,configured to show images; at least one first electrode, provided in afirst region of the electronic device; at least one second electrode,provided in a second region of the electronic device, wherein a distancebetween the first region and the front surface is larger than a distancebetween the second region and the front surface; a capacitancecalculating circuit, coupled to the first electrode to calculate atleast one first capacitance generated by the first electrode and coupledto the second electrode to calculate at least one second capacitancegenerated by the second electrode, wherein the capacitance calculatingcircuit further calculates a capacitance difference between the firstcapacitance and the second capacitance; and a processing circuit,coupled to the capacitance calculating circuit, configured to determinethe touch state according to the capacitance difference.

In view of above-mentioned embodiment, a touch state of the electronicdevice can be detected via electrodes of the electronic device.

These and other objectives of the present invention will no doubt becomeobvious to those of ordinary skill in the art after reading thefollowing detailed description of the preferred embodiment that isillustrated in the various figures and drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic diagram illustrating a wearable electronic deviceaccording to one embodiment of the present invention.

FIG. 2 is a block diagram illustrating the wearable electronic deviceillustrated in FIG. 1 according to one embodiment of the presentinvention.

FIG. 3 is a schematic diagram illustrating locations of the firstelectrode and the second electrode according to one embodiment of thepresent invention.

FIG. 4 and FIG. 5 are schematic diagrams illustrating operations of thewearable electronic device illustrated in FIG. 1 according to differentembodiments of the present invention.

FIG. 6 is a block diagram illustrating the wearable electronic deviceillustrated in FIG. 1 according to another embodiment of the presentinvention.

FIG. 7 is a schematic diagram illustrating a wearable electronic devicecorresponding to the embodiment illustrated in FIG. 6.

DETAILED DESCRIPTION

In following descriptions, a plurality of embodiments are provided toexplain the concept of the present invention. Please note the componentsin following embodiments can be implemented by hardware (e.g. circuit ordevice), or implemented by firmware (e.g. a processor installed with atleast one program). Also, the components in each embodiment can beintegrated to fewer components, or be divided to more components.Furthermore, the terms “first”, “second” . . . in following embodimentsare only for defining different components, steps or parameters, but donot mean to limit the sequences thereof.

Additionally, in following embodiments, a smart watch is taken as anexample to explain the concepts of the present invention. However, thewearable electronic device is not limited to a smart watch. Furthermore,the concept disclosed by the present invention can be applied any otherkind of electronic device to detect a touch state or a wearing state ofthe electronic device rather than limited to a wearing state of awearable electronic device.

FIG. 1 is a schematic diagram illustrating a wearable electronic deviceaccording to one embodiment of the present invention. Further, FIG. 2 isa block diagram illustrating the wearable electronic device illustratedin FIG. 1 according to one embodiment of the present invention. Pleaserefer to FIG. 1 and FIG. 2 simultaneously to understand the presentinvention for more clear.

As illustrated in FIG. 1, the wearable electronic device 100 comprisesat least one first electrode T_11, T_12, T_13, T_14 and at least onesecond electrode T_21, T_22, T_23 and T_24. The first electrodes T_11,T_12, T_13, T_14 are provided in a first region R1 of the wearableelectronic device 100, and the second electrodes T_21, T_22, T_23 andT_24 are provided in a second region R2 of the wearable electronicdevice 100.

In one embodiment, the first region R1 and the second region R2 areprovided at a back side of the wearable electronic device 100. The firstregion R1 and the second region R2 are not on the same plane, and thefirst region R1 relatively protrudes from a front surface of thewearable electronic device 100 than the second region R2. Accordingly,when a user wears the wearable electronic device 100, a distance betweenthe user's skin (i.e. a surface to be detected) and the first region R1is smaller than a distance between the user's skin and the second regionR2. Accordingly, the second region R2 may not touch the user's skin whenthe first region R1 touches the user's skin.

Further, as illustrated in FIG. 2, the wearable electronic device 100comprises a capacitance calculating circuit 101 and a processing circuit103 provided in the wearable electronic device 100. The capacitancecalculating circuit 101 is coupled to the first electrodes T_11, T_12,T_13, T_14 to calculate at least one first capacitance generated by thefirst electrodes T_11, T_12, T_13, T_14 and coupled to the secondelectrodes T_21, T_22, T_23 and T_24 to calculate at least one secondcapacitance generated by the second electrodes T_21, T_22, T_23 andT_24. The capacitance calculating circuit 101 further calculates acapacitance difference between the first capacitance and the secondcapacitance. The processing circuit 103 is coupled to the capacitancecalculating circuit 101, and is configured to determine the wearingstate according to the capacitance difference.

The first electrodes T_11, T_12, T_13, T_14 and at least one secondelectrodes T_21, T_22, T_23 and T_24 are provided in the wearableelectronic device 100 and at least part of the them expose on the backside of the wearable electronic device 100. In one embodiment,protecting materials are provided to the part of the first electrodesT_11, T_12, T_13, T_14 and the second electrodes T_21, T_22, T_23 andT_24 which expose on the back side, but the user can still causecapacitance variation while indirectly touching the part. In theembodiment of FIG. 1, the wearable electronic device 100 comprises aninner region serving as the first region R1 and an outer region servingas the second region R2 surrounding the first region R1. Further, in oneembodiment, a user's skin does not touch the second region R2 while theuser wearing the wearable electronic device.

FIG. 3 is a schematic diagram illustrating locations of the firstelectrode and the second electrode according to one embodiment of thepresent invention, which is a diagram of FIG. 1 viewed in the Xdirection. As illustrated in FIG. 3, the wearable electronic device 100is a smart watch and the first region R1, the second region R2 areprovided on a back side of the wearable electronic device 100. Further,the user's skin SK usually does not touch the second region R2 when theuser wears the wearable electronic device 100. In other words, the firstregion R1 and the second region R2 are provided on a backside of thewearable electronic device 100. A thickness P1 between the first regionR1 and a front surface FS of the wearable electronic device 100 isgreater than a thickness P2 between the second region R2 and the frontsurface FS of the wearable electronic device 100. Namely, the first partP1 protrudes from the second part P2. In this embodiment, the firstregion R1 is surrounded by the second region R2.

Accordingly, when a user wears the wearable electronic device 100, adistance between the user's skin and the first region R1 is smaller thana distance between the user's skin and the second region R2. Also, asabove-mentioned, the wearable electronic device 100 can be a smartwatch, therefore the wearable electronic device 100 comprises the frontsurface FS, which can show desired information such as images ormessages. Further, in the embodiment of FIG. 3, the first region R1,which is provided at a back side of the wearable electronic device 100,comprises a sensing surface. Via the sensing surface, the user can causecapacitance variation to the first electrodes T_11-T_14 when the userwears the wearable electronic device 100. In one embodiment, the usercan cause capacitance variation to the second electrodes T_21-T_24 whenthe user wears the wearable electronic device 100, even if the secondelectrodes T_21-T_24 do not touch the user. However, the capacitancevariation which the user causes to the second electrodes T_21-T_24 maybe much smaller than the capacitance variation which the user causes tothe first electrodes T_11-T_14 while wearing the wearable electronicdevice 100.

Therefore, in such embodiment, the first capacitance generated by thefirst electrodes T_11, T_12, T_13, T_14 when the user wears the wearableelectronic device 100 (a worn state) and the first capacitance when theuser does not wear the wearable electronic device 100 are different (ataken off state). Also, the second capacitance generated by the secondelectrodes T_21, T_22, T_23 and T_24 for the worn state and the secondcapacitance for the taken off state are the same or has a smallercapacitance variation. Accordingly, the capacitance difference betweenthe first capacitance and the second capacitance for the worn state andthe capacitance difference between the first capacitance and the secondcapacitance for the taken off state are also different. Thence, theprocessing circuit 103 can determine the wearing state according to thecapacitance difference between the first capacitance and the secondcapacitance. In one embodiment, the worn state can mean the user wearthe wearable electronic device 100 in a proper manner and the taken offstate mean the user wear the wearable electronic device 100 in animproper manner.

In one embodiment, the wearing state comprises the above-mentioned wornstate and the above-mentioned taken off state. The processing circuit103 determines the wearing state is the worn state if the capacitancedifference between the first capacitance and the second capacitance islarger than a capacitance difference threshold, and determines thewearing state is the taken off state if the capacitance differencebetween the first capacitance and the second capacitance is smaller thanthe capacitance difference threshold

In one embodiment, the processing circuit 103 can further control thewearable electronic device 100 according to the wearing state. Forexample, if the processing circuit 103 detects the wearable electronicdevice 100 is recognized by the user (e.g. by password or finger print)in the worn state, the processing circuit 103 may switch the wearableelectronic device 100 from a recognized state to a non-recognized statewhen the wearable electronic device 100 changes from the worn state tothe taken off state. If the user needs the wearable electronic device100 to enter the recognized state again in the non-recognized state, theuser must be recognized one more time. Briefly, the wearable electronicdevice 100 cannot be used to pay after the user has been recognized inthe worn state and then takes off the wearable electronic device 100. Bythis way, it can be prevented that the wearable electronic device 100 isstolen and used to pay after the user has been recognized by thewearable electronic device 100 while wearing it.

In another embodiment, the user's skin SK touches only partial of thesecond region R2 when the user wears the wearable electronic device 100.Therefore, the first capacitance and the second capacitance aredifferent for the worn state and for the taken off state. In such case,the capacitance difference between the first capacitance and the secondcapacitance for the worn state and the capacitance difference betweenthe first capacitance and the second capacitance for the taken off stateare still different. Therefore, the processing circuit 103 can determinethe wearing state according the capacitance difference.

FIG. 4 and FIG. 5 are schematic diagrams illustrating operations of thewearable electronic device illustrated in FIG. 1 according to differentembodiments of the present invention. However, FIG. 4 and FIG. 5 areonly examples for explaining and do not mean to limit the scope of thepresent invention.

As illustrated in FIG. 4, the first electrodes T_11-T_14 are served asnon-direct contactors for transmitters TX1-TX4 and the receiver RX1.Non-direct contactors mean the first electrodes T_11-T_14 are notcoupled to the transmitters TX1-TX4 and the receiver RX1, but the usercan still cause change of the electric field or the capacitance betweenthe transmitters TX1-TX4 and the receiver RX1 when the user's skintouches or approaches one of the first electrodes T_11-T_14. Forexample, if the user touches T_11, the reading result from the receiverRX1 will be altered when a driving signal is provided from thetransmitter TX1.

Via respectively providing driving signals to the transmitters TX1-TX4at different timings, the receiver RX1 can correspondingly generatetouch sensing signals at different timings. By this way, the firstcapacitance generated by the first electrodes T_11-T_14 can becalculated at different timings. Similarly, the second electrodesT_21-T_24 are served as non-direct contactors for the transmittersTX1-TX4 and the receiver RX2. Via respectively providing driving signalsto the transmitters TX1-TX4 at different timings, the receiver RX2 cangenerate touch sensing signals at different timings. By this way, thesecond capacitance generated by the second electrodes T_21-T_24 can becalculated at different timings. The driving signal can be provided thecapacitance calculating circuit 101 illustrated in FIG. 2.

In such structure, via respectively providing driving signals todifferent transmitters at different timings, the receiver cancorrespondingly generate touch sensing signals at different timings. Bythis way, the first capacitance generated by the first electrodesT_11-T_14 and the second capacitance generated by the second electrodesT_21-T_24 can be calculated at different timings.

As illustrated in FIG. 5, in another embodiment, the first electrodeT_11 serves as a transmitter TX1. Further, the first electrodes T_12,T_13 respectively serves as receivers RX1, RX2, to generate touchsensing signals corresponding to the electric field generated by thefirst electrode T_11. The electric fields generated by the firstelectrode T_11 are different for the worn state and the taken off state,thus the first capacitances generated by the first electrodes T_11, T_12and T_13 are different for the worn state and the taken off state. Thefirst electrode T_14 can also follow the same rule. Accordingly, viarespectively providing driving signals to the first electrodes T_13 andT_14 at different timings, the first capacitances of the firstelectrodes T_11-T_14 can be calculated. The second electrodes T_21-T_24can use the mechanism illustrated in FIG. 5 as well. Also, in theembodiment of FIG. 5, the processing circuit 103 can further calculatebiological information according to signals (e.g. the above-mentionedelectric field) flowing between the transmitter and the receiver.

In one embodiment, a wearing posture including a wearing location and awearing angle can further be determined by the first capacitances or thesecond capacitances. Please refer back to FIG. 3, the wearing locationcan mean a relative location between the first region R1 and the skinSK, and the wearing angle can mean the relative angle between the firstregion R1 and the skin SK. Different wearing angles or differentlocations may cause different first capacitance and/or the secondcapacitance variation. Therefore, the processing circuit 103 candetermine the wearing location or the wearing angle according to thefirst capacitance variation and/or the second capacitance variation. Inone embodiment, such as the embodiment illustrated in FIG. 6, thewearable electronic device 100 further comprises a light sensing device601 configured to generate at least one light sensing signal. Theprocessing circuit 103 calibrates the light sensing signal according tothe wearing location or the wearing angle. The light sensing device 601can be configured to sense the biological information such as heartrate.

FIG. 7 is a schematic diagram illustrating a wearable electronic devicecorresponding to the embodiment illustrated in FIG. 6. As illustrated inFIG. 7, the wearable electronic device 100 comprises lights sourcesL_1-L_4 and image sensors IS_1-IS_4. The image sensors IS_1-IS_4 areprovided at a center of the wearable electronic device 100. Also, thelights sources L_1-L_4 are respectively provided between the edge of thefirst region R1 and the first electrodes T_11-T_14. The image sensorsIS_1-IS_4 can capture images (or named light sensing signal) based onthe light generated by the lights sources L_1-L_4. Also, the processingcircuit 101 can calculate biological information according to theimages. Further, in one embodiment, the processing circuit 103calibrates the light sensing signal according to the wearing location orthe wearing angle. For example, if the wearing location or the wearingangle means that the skin SW firmly touches the first electrode T_11 butdoes not touch the first electrode T_14, a higher weighting is providedto the light sensing signal sensed by the image sensor IS_1 and a lowerweighting is provided to the light sensing signal sensed by the imagesensor IS_4. In one words, the processing circuit 103 further determineswhich one of the light sensing signals is reliable according to thewearing location or the wearing angle.

In view of above-mentioned embodiments, the wearable electronic deviceprovided by the present invention can be illustrated as: a wearableelectronic device with a function of detecting a wearing state,comprising: a processing circuit 103, configured to receive a firstgroup of touch sensing signal and a second group of touch sensingsignal. The first group of touch sensing signal can mean the signalswhich the first electrodes T_11-T_14 generate responding to the drivingsignals generated by the capacitance calculating circuit 103. Also, thesecond group of touch sensing signal can mean the signals which thesecond electrodes T_21-T_24 generate responding to the driving signalsgenerated by the capacitance calculating circuit 103.

The first group of touch sensing signal comprises a plurality of firsttouch sensing signals and the second group of touch sensing signalcomprises at least one second touch sensing signal. That is, a number ofthe first electrodes T_11-T_14 can be more than one. Also, a number ofthe second electrodes T_21-T_24 can be one or more than one. Each one ofthe second touch sensing signal respectively corresponds to one specifictouch sensing signal of the first touch sensing signals. In oneembodiment, the specific touch sensing signal is generated by one of thefirst electrodes which is closest to the second electrode correspondingto the specific touch sensing signal. For example, in the embodiment ofFIG. 1, the specific touch sensing signal corresponding to the secondelectrode T_21 is generated by the first electrode T_11, which is thefirst electrode closest to the second electrode T_21. Also, theprocessing circuit 103 determines a wearing location or a wearing angleof the wearable electronic device according to differences between thefirst touch sensing signals (e.g. first capacitance variation). Besides,the processing circuit 103 determines the wearing state according todifferences between the first touch sensing signals and the second touchsensing signals (e.g. capacitance difference between the firstcapacitance and the second capacitance).

Also, the processing circuit 103 determines whether the wearableelectronic device has the worn state or the taken off state according towhether the difference between the first touch sensing signals and thesecond touch sensing signals exceed a difference threshold. Thedifference threshold for determining the worn state and the taken offstate is larger than the differences between the first sensing signals.That is, the processing circuit 103 determines whether wearableelectronic device has the worn state or the taken off state based onwhether the first capacitance and the second capacitance has a largecapacitance difference. Also, the processing circuit 103 determines thewear location or the wear angle based on smaller first capacitancevariation. By this way, the processing circuit 103 can clearly determinethe worn state and the taken off state, and can clearly determine thewear location or the wear angle.

In view of above-mentioned embodiments, a wearing state, a wearinglocation, a wearing angle of the electronic device can be detected viaelectrodes of the electronic device, thus the problem caused by animproper wearing manner can be improved. Also, the present inventionprovides a more strict security mechanism according to the wearingstate.

Those skilled in the art will readily observe that numerousmodifications and alterations of the device and method may be made whileretaining the teachings of the invention. Accordingly, the abovedisclosure should be construed as limited only by the metes and boundsof the appended claims.

What is claimed is:
 1. An electronic device with a function of detectinga touch state, comprising: a front surface, configured to show images;at least one first electrode, provided in a first region of theelectronic device; at least one second electrode, provided in a secondregion of the electronic device, wherein a distance between the firstregion and the front surface is larger than a distance between thesecond region and the front surface; a capacitance calculating circuit,coupled to the first electrode to calculate at least one firstcapacitance generated by the first electrode and coupled to the secondelectrode to calculate at least one second capacitance generated by thesecond electrode, wherein the capacitance calculating circuit furthercalculates a capacitance difference between the first capacitance andthe second capacitance; and a processing circuit, coupled to thecapacitance calculating circuit, configured to determine the touch stateand a wearing state according to the capacitance difference; wherein thewearing state comprises a worn state and a taken off state, wherein theprocessing circuit further determines the wearing state is in the wornstate if the capacitance difference is larger than a capacitancedifference threshold, and determines the wearing state is in the takenoff state if the capacitance difference is smaller than the capacitancedifference threshold.
 2. The electronic device of claim 1, wherein theelectronic device comprises an inner region serving as the first regionand an outer region serving as the second region.
 3. The electronicdevice of claim 2, wherein the outer region is surrounding the innerregion.
 4. The electronic device of claim 2, wherein the inner region isprovided to a first part of the electronic device and the outer regionis provided to a second part of the electronic device, wherein the innerregion and the outer region are provided to a first surface of theelectronic device, wherein the first part is more protruding than thefront surface of the electronic device, wherein the front surface isopposite to the first surface.
 5. The electronic device of claim 1,further comprising: at least two light sources and at least one opticalsensor, wherein the optical sensor senses light generated from the lightsources to respectively generate light sensing signals; wherein thecapacitance calculating circuit further calculates a first capacitancevariation based on the first capacitance and a second capacitancevariation based on the second capacitance; wherein the processingcircuit further determines which one of the light sensing signals isreliable according to the first capacitance variation or the secondcapacitance variation.
 6. The electronic device of claim 1, wherein atleast one of the first electrode serves as at least one transmitter andat least one of the first electrode serves as at least one receiver,wherein the processing circuit further calculates biological informationaccording to signals flowing between the transmitter and the receiver.7. An electronic device with a function of detecting a touch state,comprising: a front surface, configured to show images; at least onefirst electrode, provided in a first region of the electronic device; atleast one second electrode, provided in a second region of theelectronic device, wherein a distance between the first region and thefront surface is larger than a distance between the second region andthe front surface; a capacitance calculating circuit, coupled to thefirst electrode to calculate at least one first capacitance generated bythe first electrode and coupled to the second electrode to calculate atleast one second capacitance generated by the second electrode, whereinthe capacitance calculating circuit further calculates a capacitancedifference between the first capacitance and the second capacitance; aprocessing circuit, coupled to the capacitance calculating circuit,configured to determine the touch state according to the capacitancedifference; and at least two light sources and at least one opticalsensor, wherein the optical sensor senses light generated from the lightsources to respectively generate light sensing signals; wherein thecapacitance calculating circuit further calculates a first capacitancevariation based on the first capacitance and a second capacitancevariation based on the second capacitance; wherein the processingcircuit further determines which one of the light sensing signals isreliable according to the first capacitance variation or the secondcapacitance variation.